There's been a rediscovery of a lava cave running under Hebron Christian College's playing field.
Some staff were aware the cave exists but it was closed when the school took over the site in 1980.
The cave is about 40m long and 2m high in places.
It starts in the lower corner of the grounds and runs across the lower field.
Lava Cave enthusiast Peter Crossley entered the cave around 30 years ago before it was covered over.
He revisited the site as part of a project to map Auckland's 200 lava caves.
They were shocked at what they found inside.
"The only thing that's changed is all the rubbish that's in there.
"I was shocked at how much is in there - it was pretty disgusting," he told the New Zealand Herald.
Mr Crossley and his colleagues removed the debris, which is believed to have been dumped before the site was closed.
The rubbish included paint tins, soft-drink bottles, wheels of a pram and spouting.
The school's staff and students are excited to explore the cave.
Source: NZ news